SDL_image: Fixed build

SDL Commits
1 
From 60d1988bce0e9f16dbb53875288c42be810b0e50 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 2 Aug 2023 08:48:45 -0700
Subject: [PATCH] Fixed build

---
 src/IMG_xcf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/IMG_xcf.c b/src/IMG_xcf.c
index 0f14882b..ac5e4e46 100644
--- a/src/IMG_xcf.c
+++ b/src/IMG_xcf.c
@@ -587,7 +587,7 @@ static unsigned char * load_xcf_tile_rle (SDL_RWops * src, Uint64 len, int bpp,
           t += 2;
         }
 
-        if (((size_t) (t - load) + length) >= read) {
+        if (((Sint64) (t - load) + length) >= read) {
           break;  /* bogus data */
         } else if (length > size) {
           break;  /* bogus data */
@@ -606,7 +606,7 @@ static unsigned char * load_xcf_tile_rle (SDL_RWops * src, Uint64 len, int bpp,
           t += 2;
         }
 
-        if (((size_t) (t - load)) >= read) {
+        if (((Sint64) (t - load)) >= read) {
           break;  /* bogus data */
         } else if (length > size) {
           break;  /* bogus data */